Method for producing wash-and-wear fabrics which are wholly or in part of animal origin



United States Patent METHOD FOR PRODUCING WASH-AND-WEAR FABRICS WHICH ARE WHOLLY OR IN PART OF ANIMAL ORIGIN Werner Von Bergen, North Caldwell, and Harold W. Wolf, Clifton, N.J., assignors to J. P. Stevens 8; Co., Inc., New York, N.Y., a corporation of Delaware No Drawing. Filed Mar. 29,, 1960, Ser. No. 18,261

10 Claims. (Cl. 8-128) .This invention relates to a method of treating animal materials or fibers such as wool and mohair for the purpose of producing a so-called wash-and-wear fabric. This invention also relates to a method of treating animal materials or fibers containing vegetable or synthetic fibers for the purpose of producing a so-called wash-and-wear fabric. More specifically this invention relates to a method of treating wool or wool containing fabrics which, upon laundering, are dimensionally stable and undergo a minimum change with respect to wrinkling and shrinking.

Fabrics consisting wholly or in part of wool have long been known to undergo undesirable changes in physical characteristics during washing, including excessive wrinkling and a pronounced tendency to felt or shrink. Accordingly it has long been sought to provide an effective process for preventing or minimizing this wrinkling and shrinking of wool. Numerous solutions to this problem have been advanced largely in the nature of chemical treatments which may be classified as halogenation, oxidation, reduction, alkaline, enzyme, or resin treatments. However, with any treatment of wool fibers to reduce wrinkling and shrinking it is essential that other changes do not occur in the wool so as to result in a diminution of the hand, appearance, color, strength and other desirable properties of the original wool or wool containing material.

For example, in connection with wool felting shrinkage which results, under certain conditions, in severe dimensional changes when many woolen items are subjected to laundering action using the various common detergents, particularly at high temperatures and rates of agitation 'in both domestic and commercial washing machines, various theorieson causes and control thereof have been discussed widely in the literature for a number of years. The prevention of felting shrinkage by the common methods and those reported in the current literature, employing various chlorinating agents, oxidizing chemicals and resin applications, has been attributed to the effect on the elastic properties of wool as well as the modification of the fiber surface and in the case of some resins to a so-called spot welding of the fibers or fiber assemblies to achieve a more rigid structure. Changes in the elastic properties have been mainly shown to be caused by the modification of the very reactive cystine linkages as well as modification of other amino acid groups including possibly hydrogen bonds and the salt linkages. The use of oxidizing agents, in particular peracetic acid, has been shown to be entirely active in disrupting the cystine portion, 'but its effect has been so drastic that its use has been limited to employment as an analytical tool for analyzing the'structure of wool. Extended treatment of wool with peracetic acid can even bring about total dissolution of the fibers in mild alkaline solutions. Other oxidizing agents such as permanganates, peroxides, and permonosulphuric acid, while producing some of the same effects as peracetic acid, possibly oxidize groups other than or in addition to the 8-8 linkage.

The literature contains numerous references to the ing the wool f ber. This is borne out by methods already 3,097,913 Patented July 16, 1963 ice proposed for commercial use where oxidizing agents are used in connection with enzymatic, chlorination or reduction reagents. Our method in particular involves a careful control of the degree of application insofar as temperature and concentration as well as the balancing effect of other oxidizing, reducing and protective agents with the peracetic acid to give adequate shrinkage control and maintain the desired properties of the woolen material. We refer especially to the balanced action of the peracetic acid on cystine and permanganate on tyrosine and other amino acid groupings. Correct controls to give adequate penetration into the fiber but not severe enough to cause disruption in subsequent processing, wearing, and maintenance of the woolen items, are necessary. Therefore we specify from a control standpoint, that the alkali solubility should not increase much over 8% above the original base value or in no instance exceed a maximum value of more than 22% when the alkali solubility is determined by standard procedure such as outlined by A.S.T.M. Committee D13 for the Testing of Textile Materials.

In order to fully understand the problem involved in the use and handling of organic peracids, especially peracetic, and the general scope of chemical reaction, especially oxidation and reduction in connection with the treatment of wool and other animal fibers, the stability of perace-tic acid and permanganate must be considered, the reaction rates with wool need to be scrutinized, the sites on the wool molecule affected by the reactive agents, and the resulting effects on the chemical and physical properties of the fiber must be fully evaluated.

Since alkali solubility is a measure of oxidation damage of wool, it has been found that a 0.2% peracetic acid solution at 21 C. will yield the following alkali solubilities.

Accordingly subsequent mention of the action of oxidizing, reducing, reforming, and cross-linking agents will have reference to the absolute alkali solubility valves and the increase over the control or untreated values (see table above).

Accordingly it is an object of this invention to provide a novel process whereby fabrics consisting wholly or in part of wool can be rendered substantially free from wrinkling and shrinking without any appreciable or detrimental alteration of the desirable characteristics of the wool. A further object of this invention is to provide a novel oxidation process for treating wool or wool containing materials including wool stock, top, yarn, woven and knitted fabrics whereby the treated wool or wool containing materials become more resistant to wrinkling and shrinking due to laundering. A further object of this invention is to provide a more rapid, simplified, and economical process for treating wool or wool containing materials so as to make the same more stable to laundering. A further object of this invention is to provide a novel process for uniformly treating wool or wool containing goods so as to make the same resistant to shrinkage whereby the wool or wool containing goods may thereafter be uniformly dyed and finished. A further object of this invention is to provide a novel process for imparting resistance to wrinkling and shrinking to wool or wool containing goods in a continuous operation utilizing equipment well known or conventional to the industry such as squeezing equipment, pads, mangles, and the 3 like. These and other objects of this invention will be apparent from the description which follows.

The novel process of this invention comprises treating keratinous textile fibers and especially wool with organic peracids such as peracetic, perbenzoic, performic, monoperphthalic, peroxy-maleic and more specifically with peracetic acid alone, or in combination with other appropriate oxidizing agents followed by a reducing treatment with alkaline earth sulfites, bisulfites and hydrosulfites which will render said keratinous fibers including wool resistant wrinkling and shrinking due to laundering. It has been found that the oxidizing solution, whether one or two oxidizers are used, should be from 0.10 to .40% by weight and, where the pad method is used, should be applied over a period of to 30 seconds at a temperature of 50 to 100 F. with 60 to 80 F. being the preferred temperature. Where the exhaust method is employed, the oxidizing solution will be applied over a period from to 60 minutes or more. The oxidizing solution has a pH of less than 7 and preferably about 4. The reducing agent may be applied as a 0.5 to 5.0% solution by weight over a period 10 seconds to 30 minutes at temperatures varying from 65 to 140 F. However, a preferred embodiment is to apply about a 1.0% solution by weight of the reducing agent at a temperature of about 100 F. over a period of about 20 minutes. In addition it has been noted that the oxidizing step may be preceded by a reducing treatment of the wool or wool containing material. Moreover, a wetting agent in concentration from 0.01 to 0.05% by weight may be employed in the oxidizing solution.

The present invention will be more completely understood by references to the following examples. In each instance all parts and percentages are by weight unless otherwise specified.

EXAMPLE I A woolen flannel 6 oz. weight per square yard of plain weave was treated continuously by being impregnated with a 0.15% peracetic acid and 0.15% potassium permanganate solution to give excellent shrinkage to laundering. The fabric was immersed at a rate so adjusted to give a time of contact of seconds. The solution is then squeezed off in a conventional pad to give a wet pick-up of peracetic acid-potassium permanganate solution of 70-75%. The fabric so treated then was immediately further processed by repeated passes in rope form through a solution of 1% sodium bisulfite and 1% sodium sulfite at 100 F. for at least minutes in a stainless steel dyeback, rinsed, extracted and dried. The laundering shrinkage after the treatment was 2.5% in area compared to 37% for the untreated flannel. The laundering shrinkage is determined by four one-hour wash cycles in a rotary washing machine using a nonionic detergent at 140 F. The alkali solubility increased only 4%, where the untreated control was 16%.

EXAMPLE II A second flannel was treated in much the same manner as Example I above except with 0.1% peracetic and 0.15 potassium permanganate, other steps remained the same. The laundering shrinkage again was excellent.

EXAMPLE III A woolen fabric was treated in the manner described in Examples 1 and 2 above, but with 0.2% peracetic acid and 0.2% potassium permanganate solution, preliminary steps and subsequent treatment being similar. The shrinkage again was excellent, namely, not over 5% in area after four l-hour washing cycles. Alkali solubility after treatment was under 20%, and therefore the increase in alkali solubility was less than 4%.

EXAMPLE IV A 100% wool fabric was given a shrink resistant treatment using 0.1% peracetic acid and 0.1% potassium per- 4 manganate solution at pH 3.5 plu Tergitol TMN, a wetting agent. The time of contact was 30 seconds. The sulfite-bisulfite after treatment in this case was carried out at 140 F. for 25 minutes. Shrinkage after four 1- hour washing cycles was 3.5% in area. Alkali solubility increase was 3%.

EXAMPLE V A woolen fabric was exposed to 0.3% peracetic acid solution containing a wetting agent for 30 seconds and then placed in 2% sodium sulfite solution at -l00 F. for 30 minutes, rinsed, extracted and dried. The area shrinkage after four l-hour washings was 3% with an alkali solubility increase of 6%. The hand of the treated fabric was agreeable.

EXAMPLE VI The wool fabric prior to being exposed to the peracetic acid solution was given a 20 minute treatment at F. in 2% sodium bisulfite solution. The fabric then was rinsed and regular 0.3% peracetic acid treatment given to the fabric by exposing the material for 30 seconds in the bath maintained at 80 F. squeezing off and finally giving the material a sulfite reducing treatment using 2% sodium sulfite solution, rinsing, extracting and drying. The shrinkage after four hours accelerated wash in nonionic detergent was less than 1% in area. Alkali solubility increased 5% to 21% (the control being at 16%).

EXAMPLE VII The same treatment as set forth in Example V was repeated except the pretreatment was made with 2% sodium sulfite. While an improved fabric was obtained, it was not better than that obtained in Example V by treating with sodium bisulfite.

Further evidence of the excellent shrink resistance properties imparted to dyed wool and wool-containing fabrics by the pera'cetic acid-potassium permanganate treating process of the present invention is indicated by the following self-explanatory tables in which wool and wool-containing fabrics were treated with peracetic acid and potassium permanganate and then subjected to a washing test. The dimensional stability imparted to the fabrics by the treatment is clearly shown by the low percentage of shrinkage which resulted.

Table I.Area Shrinkage in Percent of Peracetic Acid- Potassium Permanganate T reated (Pad Application) Dyed Flannels Resulting From Alkali Wash Test Method A. PAD APPLICATION Sample: Shrinkage after four Washes Style A 0.3 Style B c 1.2

B. CONTROL Style A 22.0 Style B 29.0

a Area shrinkage:

(warp shrinkage-j-filling shrinkage) warp shrinkage filling shrinkage 100 The warp and filling shrinkage is calculated f sional changes occurring over original dimeii iiin dlmen 80% wool-20% nylon. c 100% wool.

The alkali wash procedure referred to in Table I can be briefly outlined as follows:

Washing machine Cylinder-reversing. Make Najo-rt.

Speed, r.p.m 30'.

Load, lbs. 3.

Detergent 20 grams soap,

grams Borax, 60 cc. Calgon-30% (tetrasodium pyrophosphatte).

Water level, volume '9".

Solution temp, F 140.

Suds time, min. 40.

Rinsing Two for min.

Wet tumble 5 min.

Total time, min. 60'. Extraction 10 sec.

Drying Flatbed press till dry.

[in addition to rating wool fabrics and wool containing fabrics, previously treated by the peracetic acid proc ess of this invention as to their shrinkage resistance, as noted in Table I above, the fabrics were also given a wash and wear appearance rating according to the AATCC Tentative Test Method 88-1958. This method briefly involves the appearance rating of the washed samples when placed on :a flat surface in the manner indicalted by the AATCC manual by three trained observers, rating each test specimen independently, using a specified lighting condition. Five photographic standards (or plastic replicas) are provided in which standard No. 5 represents the best wrinkle resistance, that is, negligible or no change in surface appearance, while standardl No. 1 represents the least wrinkle resistance. The results are recorded as an average of all observations given to the nearest decimal. In the examples listed in the patent application, the wash and wear evaluations after five Fab washings were 4.5 to 5.0 when tumble dried, The results of these laundering and wash and wear tests are summarized in Table II and indicate that the washed samples would require little or no ironing.

Table II.Shrinkage in Percent aznd Wash-and-Wear Data on Peracetz'c-Acid-Potassium Permanganate Treated Flannels Resulting From Fab Wash Test Method Shrinkage in Laundering, percent Wash and Wear Evaluation 1 (AATCC Cloth Sample Three Washes Five Washes Method) After Five Fab Washes- Warp Fill Warp Fill Tumble Dry A (80% wool/% nylon) 2. 8 None 3. 3 1. 0 5. 0 3. 3 1. 0 3. 6 1. 5 4. 8 2. 8 1. 5 3. 3 2. 0 4. 8 3. 9 1. 5 5. 0 2. 5 5. 0 2. 8 None 3. 1 None 5. 0

3. 3 0. 5 3. 6 1.0 5. 0 3. 6 1.0 4. 4 1. 5 4. 8 3.1 a 0.5 3. 1 None 4. 5 3. 6 0. 5 4. 7 1. 5 5. 0 2. 8 1. 0 4. 4 2.0 5. 0

l Fab washing. 2 Sample in each instance was 22 x 18". 8 Stretch.

The Fab wash procedure referred to in Table II can be briefly outlined as follows:

Washing machine Agitator.

Make Maytag. Speed, r.p.m 47.

Load, lbs. 3.

Detergent 50 grams Fab. Water level, volume Normal, 15 gal. Solution temp, F 105.

Suds time, min. 3. i

Rinsin-g Two.

Total time, min. 2.0.

Extraction Normal. Drying Tumble dried [for 35 min. at 145 F.

It is to be noted that various modifications can be made in the novel process of this invention. The inventive process may be considered as being substantially a two step method involving (1) oxidation (perorganic 6 acid or perorganic acid and potassium permanganate combined) and (2) reduction (alkali metal sulfite or bisulphite). Alternatively the oxidation step can be preceded by a pretreatment step with an alkali metal sulfite or bisulfite solution as in Example 6 above.

Moreover, the oxidizing agent can be applied in the presence of a wetting agent of which the anionic and nonionic wetting agents can be considered as representative. A group of wetting agents which has been found practicable includes those of the sulfated alcohol type which are generally derived from unsaturated fish or vegetable oils and have from 8 to 18 carbon atoms that may or may not be of the straight chain type. A specific example is Triton 200 which is a sodium lauryl sulfate. Additional wetting agents that may be employed include the Tergitol type which are alkyl ethers of polyethylene glycols and the Tween type which are polyoxyethylene sorbitan esters of fatty acids. The aforementioned wetting agents are merely by way of example and it is evident to those skilled in the art that other wetting agents can be used. The amount of wetting agent employed can vary from 0.01% to 0.05% and more if desired.

The preferred oxidizing agents are peracetic acid and mixtures of peracetic acid and potassium permanganate. Attempts to substitute other oxidizing agents such as hydrogen peroxide, cupricsulfate, and sodium perborate for the potassium permanganate produced unsatisfactory reeral any reducing agents which is a sulfur containing compound may be used including the thiosulphates, mercaptans, hydrosulfites and the like. Alkali metals and alkali earth metals which are satisfactory in the present process include sodium, potassium, barium, calcium, magnesium, lithium, and the like.

Although the oxidizing solution is described as consisting of (1) peracetic acid or (2) a mixture of peracetic acid and potassium permanganate, best results are obtained when peracetic is present. :In fact unsatisfactory results are obtained if potassium permanganate is used exclusively as the oxidizing agent.

The oxidizing and reducing solutions may be applied by immersion, exhaustion, or padding. Moreover, a water rinsing step may be employed between the oxidizing and reducing steps, if desired.

It is also apparent that the process may be carried out in distinct steps or in a continuous manner not only in connection with fabrics but also with fibers and yarns as well as knitted, Woven, and non-woven fabrics.

If desired, the second or reducing step can be modified by adding to the reducing solution a linkage reformer such as a bifunctional compound, for example, a water soluble dibromo compound of a dicarboxylic acid, alcohol, or ketone.

Thus the novel process of this invention provides a new method for imparting shrink resistance to wool or wool containing materials resulting in (1) no appreciable reduction in fiber strength, (2) no marked increase in alkali solubility and (3) no harsh disagreeable feel or undesirable hand to the wool or wool containing materials.

While the illustrative embodiments of the invention have been described hereinbefore with particularity, it will be understood that various other modifications will be apparent to and can readily be made by those skilled in the art Without departing from the scope and spirit of the invention. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the examples and description set forth herein but rather that the claims be construed as encompassing all the features of patentable novelty which would be treated as patentable equivalents thereof by those skilled in the art to which the invention pertains.

We claim:

1. A method of imparting wash and Wear characteristics, including dimensional stability, to fabrics containing animal fibers and selected from the group consisting of wool, mohair, part wool, and part mohair fabrics comprising treating said fabrics with an oxidizing solution which is maintained at about 50 F. to 100 R, which has a concentration from about 0.10 to 0.40 percent by weight of the oxidizers, and which is selected from the group of oxidizers consisting of (a) peracetic acid and (b) mixtures of peracetic acid and potassium permanganate at a pH less than 7 and thereafter treating said fabrics with a reducing solution which is maintained at about 65 F. to 140 F., which has a concentration from about 0.5 to 5.0 percent by weight of the metal salts, and which is selected from the group consisting of alkali metal and alkali earth metal salts of (a) sulfites and (b) bisulfites.

2. The method of claim 1 in which the temperature of the oxidizing solution is maintained at about 60 F. to 80 F.

3. The method of claim 1 in which the oxidizing solution is applied by the pad method over a period from 10 to 30 seconds.

4. The method of claim 1 in which the oxidizing solution is applied by the exhaust method over a period from 20 to 60 minutes.

5. The method of claim 1 in which the oxidizing solution has a pH of about 4.

6. The method of claim 1 in which the temperature of the oxidizing solution is maintained at about 60 F. to 80 F. and the temperature of the reducing agent is at a temperature of about 100 F.

7. The method of claim 1 in which the reducing solution is added over a period of 10 seconds to 45 minutes.

8. The method of claim 1 in which the reducing solution is about 1.0 concentration, has a temperature of about 100 F. and is added over a period of about 20 minutes.

9. A method of imparting wash-and-Wear characterisitcs, including dimensional stability, to fabrics containing animal fibers and selected from the group consisting of wool, mohair, part-wool and part-mohair fabrics comprising treating said fabrics with an oxidizing solution of peracetic acid at a pH less than 7 and thereafter treating said fabrics with a reducing solution which is maintained at about F. to R, which has a concentration from about 0.10 to 0.40% by weight of the oxidizer, and which is selected from the group consisting of alkali metal and alkali earth metal salts of (a) sulfites and (b) bisulfites.

10. A method of imparting wash-and-wear characteristics, including dimensional stability, to fabrics containing animal fibers and selected from the group consisting of wool, mohair, part-wool, and part-mohair fabrics comprising treating said fabrics with an oxidizing solution which is maintained at about 50 F. to 100 F., which has a concentration from about 0.10 to 0.40% by weight of the oxidizer, and which consists of mixtures of peracetic acid and potassium permanganate at a pH less than 7; and thereafter treating said fabrics with a reducing solution which is maintained at about 65 F. to F., which has a concentration from about 0.5 to 5.0% by weight of the metal salts, and which is selected from the group consisting of alkali metal and alkali earth metal salts of (a) sulfites and (b) bisulfites.

References Cited in the file of this patent UNITED STATES PATENTS 2,369,398 Douglas Feb. 13, 1945 2,548,774 Coe Apr. 10, 1951 2,739,034 Fell Mar. 20, 1956 OTHER REFERENCES Moncriefi: Wool Shrinkage and Its Prevention, pages 289-290, The National Trade Press, Ltd., 1953, London. 

1. A METHOD OF IMPARTING WASH AND WEAR CHARACTERISTICS, INCLUDING DIMENSIONAL STABILITY, TO FABRICS CONTAINING ANIMAL FIBERS AND SELECTED FROM THE GROUP CONSISTING OF WOLL, MOHAIR, PART WOOL, AND PART MOHAIR FABRICS COMPRISING TREATING SAID FIBRICS WITH AN OXIDIZING SOLUTION WHICH IS MAINTAINED AT ABOUT 50* F. TO 100* F., WHICH HAS A CONCENTRATION FROM ABOUT 0.10 TO 0.40 PERCENT BY WEIGHT OF THE OXIDIZERS, AND WHICH IS SELECTED FROM THE GROUP OF OXIDIZERS CONSISTING OF (A) PERACETIC ACID AND (B) MIXTURES OF PERACETIC ACID AND POTASSIUM PERMANGANATE AT A PH LESS THAN 7 AND THEREAFTER TREATING SAID FABRICS WITH A REDUCING SOLUTION WHICH IS MAINTAINED AT ABOUT 65* F. TO 140* F., WHICH HAS A CONCENTRATION FROM ABOUT 0.5 TO 5.0 PERCENT BY WEIGHT OF THE METAL SALTS, AND WHICH IS SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL AND ALKALI EARTH METAL SALTS OF (A) SULFITES AND (B) BISULFITES. 